SmogRank / Spain / Castille and León / Aranda de Duero

Aranda de Duero, month by month

Aranda de Duero has a measured daily mean on 401 days since 1 January 2025. Its worst month was August 2025, at 63 US AQI (15.5 µg/m³), 325th of 2,901 cities on that month's world ranking. Its cleanest was January 2026, at 18 US AQI (3.3 µg/m³).

Every month since 2025

2026too few days for a mean (a year needs 199)100 days measured

Jan18#2,560Feb8 daysMarnoneAprnoneMay1 dayJun5 daysJul18 daysAug21 daysSep14 daysOct6 days

202536 for the year301 days measured2,243rd of 2,681 in the world

Jan24#2,323Feb17 daysMar18 daysApr22#2,783 May27#2,334 Jun52#1,391 Jul43#1,824 Aug63#325 Sep34#2,057 Oct28#2,039 Nov19#2,630 Dec25#2,792

Each square is a month's mean PM2.5 in US AQI from Aranda de Duero's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Aranda de Duero marked; each year, the year's.

Good0–50

Moderate51–100

Sensitive groups101–150

Unhealthy151–200

Very unhealthy201–300

Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Months without a mean, and why

11 months

Month	Why
Oct 2026	6 of 11 days measured; a month needs 8. The others: 3 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours).
Sep 2026	14 of 30 days measured; a month needs 21. The others: 16 with readings for part of the day (a day needs 18 hours).
Aug 2026	21 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jul 2026	18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Jun 2026	5 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks.
May 2026	1 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Apr 2026	No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2026	No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2026	8 of 28 days measured; a month needs 20. The others: 20 with under 18 hours of readings or readings that failed our checks.
Mar 2025	18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Feb 2025	17 of 28 days measured; a month needs 20. The others: 11 with under 18 hours of readings or readings that failed our checks.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Aranda de Duero's worst months

Month	US AQI	Days measured	World rank	Episode
August 2025	6315.5 µg/m³	31 of 31	325thof 2,901	Spain, Portugal and Andorra, August 2025
June 2025	529.7 µg/m³	21 of 30	1,391stof 2,508	–
July 2025	437.8 µg/m³	31 of 31	1,824thof 2,889	–
September 2025	346.1 µg/m³	28 of 30	2,057thof 3,104	–
October 2025	285.0 µg/m³	25 of 31	2,039thof 2,614	–
May 2025	274.9 µg/m³	25 of 31	2,334thof 2,826	–

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

Aranda de Duero's worst days

Day	US AQI	Episode
18 Aug 2025	13047.3 µg/m³	Spain, Portugal and Andorra, August 2025
17 Aug 2025	8326.5 µg/m³	Spain, Portugal and Andorra, August 2025
16 Aug 2025	8125.3 µg/m³	Spain, Portugal and Andorra, August 2025
28 Jul 2026	7723.3 µg/m³	–
12 Aug 2026	7723.2 µg/m³	–
19 Aug 2026	7723.0 µg/m³	–
19 Aug 2025	7722.8 µg/m³	Spain, Portugal and Andorra, August 2025
13 Aug 2026	7421.7 µg/m³	–
8 Aug 2025	7220.3 µg/m³	–
7 Aug 2025	7120.1 µg/m³	–

Daily means, the highest since 1 Jan 2025; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, Aranda de Duero, Spain, 1 Jan 2025 – 8 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/es/aranda-de-duero/history (accessed 12 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Aranda de Duero now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 20:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).